1. Field of the Invention
The present invention relates to an engine intake manifold that includes an intake air distribution box having an intake inlet and a plurality of intake branch pipes that are provided in a vertical arrangement for connection to a side wall of the intake air distribution box. The downstream ends of the intake branch pipes are connected to a plurality of corresponding intake ports of an engine, and a funnel is formed at the upstream end of each of the intake branch pipes so as to be disposed within the intake air distribution box.
2. Description of the Prior Art
Generally, in an intake manifold, when the intake air blows back the fuel that is present in the blown-back gas in some cases collects on the base within an intake air distribution box. When the fuel evaporates, it is taken into the engine together with the intake air. However, in the case where the fuel resides on the base within the intake air distribution box when the engine is shut off, the fuel evaporates and leaks outside, thus creating a loss.
The present invention has been carried out in view of the above-mentioned circumstances, and it is an object of the present invention to provide an engine intake manifold that can prevent fuel loss by promptly supplying the fuel that has collected on the base within an intake air distribution box to the engine.
In order to achieve the above-mentioned object, in accordance with a first aspect of the present invention, an engine intake manifold includes an intake air distribution box having an intake inlet, and a plurality of intake branch pipes that are provided in a vertical arrangement, connected to a side wall of the intake air distribution box. The downstream ends of the intake branch pipes are connected to a plurality of corresponding intake ports of the engine, a funnel being formed at the upstream end of each of the intake branch pipes which are disposed within the intake air distribution box. A fuel collector is formed on the base of the intake air distribution box, and a fuel draw-up hole communicating with the fuel collector, is provided in a side wall of the lowest funnel adjoining the fuel collector.
In accordance with the above-mentioned arrangement, when the fuel collects in the fuel collector within the intake air distribution box, due to the phenomenon of intake air blow-back during operation of the engine, the fuel draw-up hole draws up the fuel promptly to supply it to the engine due to the action of the negative intake pressure generated within the lowest funnel, thereby preventing loss of the fuel. Moreover, the length of the fuel draw-up hole provided in the lowest funnel can be minimized.
Furthermore, in accordance with a second aspect of the present invention, an engine intake manifold has the fuel collector formed from a recess formed on the base of the intake air distribution box.
In accordance with the above-mentioned second aspect, since the fuel that, together with the blow-back gas, has flowed back into the intake air distribution box, is collected in the recess, the fuel loss due to dispersion of the fuel can be prevented.